Question

If six men can do a piece of work in 6 days, then 3 men can do same work in

(a) 10 days
(b) 12 days
(c) 15 days
(d) 18 days

Answer 1

Let the required number of days be x.

Number of days is inversaly proportional to the number of men.

According to the question,

$$\begin{gathered} 6:3::x:6 \\ \Rightarrow \frac{6}{3}=\frac{x}{6} \\ \Rightarrow \frac{6\times 6}{3}=\frac{x\times 6}{6} \\ \Rightarrow \frac{36}{3}=x \\ \Rightarrow x=12 \end{gathered}$$

Thus, 3 men can do same work in 12 days.

Hence, the correct option is (b).